CHICAGO – On Thursday, LaMarcus Aldridge returned, and the Trail Blazers got a much-needed win over Atlanta to end a three-game losing streak. On Friday, they faced a bigger test, a matchup in Chicago against the tough-minded Bulls on the back end of a back-to-back.

They passed with flying colors.

Even with Aldridge struggling to hit shots, the Blazers deftly handled the Bulls for a 91-74 victory at the United Center. The Blazers combined strong defense with timely shot-making to achieve one of their most complete wins of the season, even as they continue their battle to hold onto their playoff position in the Western Conference.

“It was a win that we needed,” point guard Damian Lillard said. “We knew they were coming out competing on both ends of the floor. We did a great job defending, we executed against a really tough defense. It was a big game that we needed to win, and we took care of business.”

The Blazers (47-27) ended their final big road trip of the season 2-3, but might have regained some of their early-season mojo. The victory over the Bulls was their first on the road against a team with a winning record since Jan. 18 at Dallas, but at this point in the season, with eight games remaining and a playoff berth still not assured, those kinds of details are trumped by simply getting wins.

“We all know where things are in the standings and playoffs, and every game is critical,” Blazers coach Terry Stotts said. “We let a couple get away on this trip. I didn’t have to say anything. The team knows where we are, what we need to do.”

The Blazers held Chicago (40-32) to 39.3 percent field goal shooting, and the 74 points the Bulls scored were a season-low for a Blazers opponent. Robin Lopez keyed the defense by blocking five shots, Aldridge added four steals, and the Blazers felt locked in and connected all game.

“I think that’s just another example of everybody being there for one another,” said Lopez, who added 13 points and nine rebounds. “That pretty much is what defense is to me. When you know there’s somebody behind you, that gives you more confidence to perform on defense, to be a little more aggressive.”

The Bulls are no offensive juggernaut, but they are certainly one of the NBA’s top defenses, entering the game ranked No. 2 in points against at 91.9. The Blazers didn’t come near their 106.1-point average, but they ran their offense efficiently and shot 10 for 22 from three-point range (45.5 percent) as they continued to regain the outside shooting touch that seemed to have deserted them in March.

Mo Williams followed his 11-assist effort against Atlanta by scoring a team-high 18 points and shooting 7 for 12 from the field. The Blazers improved to 22-5 when Williams scores in double figure.

“The way Mo played last night and tonight, we need his scoring, we need his energy,” Stotts said. “Defensively, I thought he worked really hard on (D.J.) Augustin and making it really difficult on him. To beat a team like Chicago, you need everybody to be locked in. It’s well chronicled that when he’s able to score for us, our success is pretty high.”

Williams scored 12 points in the first half to stake the Blazers to a 47-36 halftime lead, then they really put the pedal down with a 15-2 run to start the third quarter fueled by three-pointers, with Nicolas Batum making two and Wesley Matthews another.

The Blazers got double-figure scoring from six players, including reserve forward Thomas Robinson, who had his second consecutive 10-point game.

“I thought the blend of different combinations went well,” Stotts said.

The only thing really missing was a big scoring night from Aldridge, who shot 2 for 10 from the field and finished with five points. But Aldridge contributed in other ways, getting 13 rebounds and four steals and also commanding enough defensive attention to generate good shots for his teammates.

“I just want to bring what I can for the team,” he said. “Tonight it was more defense and rebounding and trying to be active in the lane and making things tough defensively. Some nights you have to do different things.”

Aldridge admits he was sore after playing 32 minutes against Atlanta in his first game action since injuring his back on March 12, but it would’ve taken a lot to keep him from playing at this crucial juncture.

“As long as I woke up and I could walk, I was going to play,” he said. “I woke up and I was sore. We did some things this morning. But once I got here tonight, I was good to go.”

Things hardly get easier the Blazers as Memphis, one of the teams chasing them and a team that has already beaten them twice by double digits, comes to Portland on Sunday for a crucial game for both teams.